Psoriatic Arthritis

Common: Incidence 1/100 (up to 30% among pts w/ Psoriasis)
  • Psoriasis appears first 85% of time
Dx:  <5 joints occurring in asymmetric fashion, plus skin psoriasis
  • Usually medium- or large-joint invlovement
Can sometimes mimic RA with small-joint polyarthritis
  • RF maybe positive, even CCP
Suspect especially if:
  • Nail pits [see pix below]
  • Prominent DIP disease
  • Dactylitis [see pix below]
  • Enthesopathy (esp. inflammation at insertion of Achilles tendon)
  • Tendonitis of hand flexors

See also postings Monoarticular Arthritis and Polyarthralgias.

Nail Pits


Dactylitis (“sausage digits”)